 Techline-Dec.08-Oil Coolers-Part III: Installation tips and types of coolers
This article will continue in the next thread
I can’t tell you the number of dented front fenders we’ve repaired over the years because a telescoping front end slams the fender into a recently installed oil cooler that’s mounted on the upper end of the frame’s front downtubes! Whenever you install an oil cooler in this location, always compress the front end to see if there’s enough clearance between the fender and cooler. Jagg coolers don’t have this problem since they mount near the lower front motor mount or on the side of the frame’s downtube. Putting an oil cooler down by the front motor mounts can be risky and downright dangerous below the frame. Hitting a curb or other obstruction can dump all your engine’s oil onto the ground. Unnoticed, this will demo your engine due to lack of lubrication or (even worse) cause an accident due to an oil-soaked and slippery rear tire.
Of course, manufacturers like Jagg and H-D are very aware of this. Their coolers come with bracketry to keep them out of harm’s way. If you’re mounting an oil cooler that does not have this safety feature, be aware that a lower frame member must protect the cooler. Furthermore, oil lines must be located away from other parts that may wear through them over time. Do not locate an oil cooler in an area with obstructed airflow.
Unbelievable as it sounds, I have found oil coolers inside fairings and behind lower fairings. Reduced airflow equals reduced cooling.
Return or Feed Mounting
On pre-Twin Cam Harleys (1998 and earlier rubber-mounts, and 1999 and earlier Softails), the engine’s oil is filtered after it passes through the engine and comes out the return side of the oil pump. On these external, gear-driven oil pump-equipped bikes, the oil cooler should interrupt the return oil line, which goes from the engine to the oil tank. You want the return line from the oil pump feeding into one side of the oil cooler. A second line exits from the other side of the oil cooler and goes to the return oil fitting on the oil tank. The Twin Cam is the first Harley to filter its oil before it goes through and lubricates the engine. The oil filter is located on the oil feed, which goes from the oil tank to the engine.
The majority of oil coolers are generic in that it does not matter which cooler nipple is used for the feed into the cooler and which one is the return out of the oil cooler. On a few coolers, there is a directional oil flow that should be followed with a feed-and-return nipple on the cooler that should be marked as such for the observant mechanic. Always read the instructions and check the cooler for directional intake and outflow indicators. The vast majority of oil coolers, including Jagg, have no In or Out. Whatever port the oil enters though, it will exit from the other one. However, some adapter plates for mounting the cooler may have a specified inlet and outlet. If so, they will be clearly marked, and the installation instructions will also indicate this is necessary. There may also be helpful suggestions for oil line routing for ease of fitment and installation.
The design of Jagg adapter plates specifically flows oil through the oil filter before the oil cooler. This is done because less restriction occurs since the oil is warm and thus less viscous. This is significant for the Twin Cam because of the oil filter’s placement on the pressure-feed side of the oiling system. Therefore, the Jagg adapter offers less pressure drop than any other oil filter adapter due to this purposeful directional flow characteristic. This flow path through the filter first contributes to the total system of turbulation combining with less pressure drop that makes the Jagg cooler advantageous over competitors at this time. In a nutshell, cool oil is delivered to where it needs to go.
Types of Jagg Oil Coolers
There are three basic types of Jagg vertically mounted oil coolers for Harley-Davidson applications. The first is the Slimline (#1200 and #1250) oil cooler. Smooth end caps help this cooler blend with the frame for a clean, streamlined look. The cooler mounts to the left downtube and is spaced away from the frame to allow airflow to both the oil cooler and engine’s cylinders. It mounts to the frame using highly durable Uralite mounts, which have a shock absorbing effect and clean styling. The Slimline’s six-tube cooler with a two-pass design offers three times more cooling surface than Jagg’s closest competitor — with special in-line turbulators.
The second is the Deluxe oil cooler (#1000 and #1050). The Deluxe also attaches to the left frame downtube using Uralite mounts and is spaced away from the frame for superior cooling to both the cooler and engine. The Deluxe’s six-tube, two-pass design offers, like the Slimline, three times the cooling surface of its closest competitor. Special in-line turbulators add to the cooler’s efficiency with minimal oil pressure loss or restriction. Its aluminum construction has a durable, powdercoated finish. Billet-aluminum end caps with machined fins match and complement the style of the engine’s cooling fins.
The third cooler (#2100 black and #2180 chrome for Softail 2000 and later; #2200 black and #2280 chrome for FLH 1999 and later) is my favorite and is, of course, the 10-row oil cooler. I prefer black when it comes to an oil cooler. Chrome is a heat transfer barrier that will hold more heat in than bare metal. Polishing is okay, as it is not a barrier to heat transfer. However, it’s tough — as in real tough — to polish a cooler without disturbing the fins and wreaking havoc with the heat transfer components. Now, it is true that black powdercoating is also a heat transfer barrier, but nothing like the chromium. Of course, the parts of the oil cooler that are actually responsible for exchanging the heat have only a negligible coating on the leading and trailing edges of the fins. Powdercoating is extremely durable, long-lasting, and the best choice, in my opinion, for a functional oil cooler protective covering.
Jagg’s coolers are all available in black: some with chrome accenting and others with removable chrome accents. The Deluxe coolers are available in black or chrome. On chrome Jagg coolers only the outside framework is chromed. Jagg does not saddle the rows and fins with this heat barrier because the heat exchange function is much more important than making a mere chrome bauble. The available chrome accents on some Jagg coolers fit on the sides, but not on any functioning component. They are also a separate item (#CH-160) to dress up some models of the black coolers. They require heat-resistant silicone adhesive to attach to the sides of the #1200 and #1250 Slimline coolers, the #1270 FLHT low-mount coolers, and the #300 FLH Twin Cam 10-row, low-mount oil coolers. The vertical 10-row coolers mount on the left downtube frame member, like the Slimline and the Deluxe coolers, except it alone mounts parallel with the airflow, not against it as with the other Jagg coolers. The in-line mounting orientation ensures that the cooler takes up as little space as possible, while the airfoil creates a low-pressure zone that draws air through the oil cooler. With the air rushing by the oil cooler in an area of relatively high pressure, the airfoil simultaneously creates a low-pressure area behind the airfoil and draws air through the cooler. The greater the speed of the air passing the airfoil, the greater the volume of cooling air drawn through the cooler.
The turbulated 10-row oil cooler’s two-pass design offers significantly more cooling surface than other H-D design oil coolers, again with the all-important minimal oil pressure loss or restriction. Jagg’s horizontal oil coolers mount near the front motor mounts but above the lowest frame member behind the front fender. The #2300 series FLH Twin Cam low-mount 10-row coolers do not have an attached airfoil since they face directly into the airstream. Also available are #1270 and #1280 series six-row FLH Twin Cam low-mount coolers, as well as the horizontal six-row #1290 series for Softails. Lastly, Jagg sells a universal mount (#3080) turbulated mega 14-row oil cooler that measures 8-1/4" x 5-1/4" x 1-1/2".
As for Jagg’s thermostat, the actuator begins to move at 185 degrees Fahrenheit and by 195 degrees is fully actuated, plugging the bypass hole and directing 100 percent of the oil’s flow to the oil cooler.
Oil coolers also add some oil capacity to a Harley-Davidson. A six-row oil cooler will add approximately 6 ounces of oil capacity while the 10-row oil cooler will add approximately 8 ounces. I highly recommend a turbulated oil cooler with multiple rows, 10 or more being preferable, with minimal pressure drop on all Harley-Davidsons, and I specifically recommend those manufactured by Jagg. I feel that they are a prerequisite for any stock application. They are an absolute must for any performancing options. Oil coolers just make sense and pay for themselves by decreasing the incidence of detonation and by prolonging repair intervals.
This article continues in the next thread. Check the back issue for pix and more information. |
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